1. Field of the Invention
The present invention generally relates to a fixing apparatus and an image-forming apparatus that incorporates the fixing apparatus.
2. Description of the Related Art
A conventional electrophotographic image-forming apparatus uses a fixing unit that includes upper and lower rollers and separators. The upper and lower rollers abut each other with a predetermined nip formed between them, and rotate while being heated. The separators separate a fixed recording medium from the upper and lower rollers to prevent the recording medium from becoming tacked to the upper and roller rollers.
The separators are disposed in such a way that a predetermined gap is created between the separator and a corresponding roller. The separator includes a plurality of tongues and spacers. The tongues are mounted on, for example, a mounting board and aligned in a longitudinal direction to act directly on the recording medium to detack the recording medium from the roller. The spacers are in pressure contact with the roller and maintain a predetermined gap between the roller and the tongues. The separator is rotatable about an axis parallel to a rotational shaft of the roller and is urged against the roller. As a result, even when the roller changes in diameter due to thermal expansion, the separator maintains the gap.
A problem with the aforementioned conventional fixing unit is that the recording medium may be caught by some of the tongues to become jammed. When the roller changes in diameter at its longitudinal end portions due to thermal expansion, the spacer at one end portions moves out of contact with the roller, failing to maintain the predetermined gap between the tongues and the roller across the length of the roller.